Step and repeat machine.



L. J. R. HOLST & O. CHOUINARD.

STEP AND REPEAT MACHINE.

APPLIGATIGN FILED APRJV, 1009.

1,131,629. Patented Mar. 9, 1915.

6 SHEETSSHBET 1.

WITNESSES I MUM INVENTORS ATTORNEYS THE NORRIS PETERS CO PHOTO LITHO WASHINGTON D c.

L. J. R. HOLST & 0. CHOUINARD.

STEP AND REPEAT MACHINE.

APPLICATION FILED APR.17, 1909.

6 SHEETS-SHEET 2.

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El Li i? WITNESSES: uvmvrons 8 W a... QMQM .7 M- f ATTORNEY THE NORRIS PETERS CO,PHOTO'LI1HO.. WASHINGTON, a. c

L. J. R. HOLST & 0. CHOUINARD.

STEP AND REPEAT MACHINE.

APPLICATION FILED APR.17, 1909.

1,131,629, Patented Mar. 9, 1915.

6 SHEETS-SHEET 3.

IN VE N TORS W/TNESSES: M

TTOHIV E Y L. J. R. HOLST & O. CHOUINARD.

STEP AND REPEAT MACHINE.

APPLICATION FILED APR.17, 1909.

1,131,629. Patented Mar. 9, 1915.

6 SHEETSSHEET 4.

WITNESSES 7 8m I HMMMMHMMMMMMIMW MWMMMMMM! All A TTORN E Y L. J. R. HOLST & O. CHOUINARD.

STEP AND REPEAT MACHINE.

APPLICATION FILED APR.17, 1909.

1,131,629. Patented Mar. 9, 1915.

6 SHBETS SHEET 5.

WITNESSES. IN E 881mm k Q M474 'ATTOR/VEY L. J. R. HOLST & 0. OHOUINARD. STEP AND REPEAT MACHINE.

APPLICATION FILED APR.17, 1909.

1,131,629, Patented Mar.9, 1915.

6 SHEETSSHBET e.

5 X/W/wW B I A TTOH/VEV THE NORRIS PETERS CO PHOTO LITHO WASHINGTON, D C.

UNITED STATES PATENT OFFICE.

LOUIS J. R. HOLST AND OSCAR CHOUINARD, OF NEW YORK, N. Y., ASSIGNORS, BY MESNE ASSIGNMENTS, TO LITHOTEX CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

STEP AND REPEAT MACHINE.

Application filed April 17, 1909.

To all whom it may concern:

Be it. known that we, LOUIS J. R. HOLST, a citizen of the United States, and OSCAR CHOUINARD, a subject of the King of Great Britain and Ireland, residents of the borough of Brooklyn, city of New York, county of Kings, and State of New York, have 1nvented certain new and useful Improve ments in Step and Repeat Machines, of which the following is a specification.

Our invention relates to step and repeat machines intended to build up perpendicularly and laterally upon a plate from a unit.

element or design, a plurality of the said unit designs; and more specifically, the in" vention relates to step and repeat machlnes to be used for photographically reproducing an element or design a numbenof times upon a sensitized plate by successively pro jecting, by means of a lens, images of the element or design upon successive portions of the sensitized plate so as to produce a plate containing a number of reproductions of such element or design of a predetermined size.

It is highly desirable, for obvious reasons, toprint from a single printing surface a number of prints of one or more designs, and in producing such a printing surface, it has been proposed to use a machine for step ping and repeating the design in which the sensitized surface to be used is that of a stone or zinc plate held rigid in a frame on or adjacent to which is mounted a suitable holder for a transparent plate bearing the design to be reproduced, the holder being arranged to move in and out toward the sensitized surface so as to press the design plate against the sensitized surface, in which po sition an exposure of the design is made, the holder also being provided with means for moving it horizontally and vertically in a plane parallel to the sensitized surface so as to reproduce the design on different portions of the surface. But such machines have been found unsatisfactory and for many classes of work, have been found entirely impractical. Such machines require heavy parts for supporting the sensitized surface in po sition and holding it sufliciently firm to permit the pressing of the design plate against it, and they further require means for pressing the design plate into contact with the sensitized surface in such a manner as to se- 65 cure, as nearly as possible, with such a ma- Specification of Letters Patent.

Patented Mar. 9, 1915.

Serial No; 490,573.

reproduction of the design in sizes varying from the original design. In order to obvi' ate some of these difficulties, it has been proposed to provide a step and repeat machine in which a lens. is utilized between the unit design and the sensitized plate, the lens, plate and unit design being relatively adjustable along the optical axis for the purpose of projecting the images in clear-cut lines and in sizes varying from the original.

design; relative movement being provided between the sensitized surface on the one hand and the lens and unit design on the other, as in the case of the first machine. But in this last machine, the lens and the sensitized surface holder and the unit design holder are each mounted on separate carriages, separately and independently adjust able along the line of projection. This feature renders such a machine highly undesirable, if not entirely impractical for most purposes for which step and repeat machines are desired. For example, unit designs furnished by an artist or designer are frequently of a size in width and length which is not an even factor of either the width or length of the plate upon which the designs are to be reproduced; and if it is desired to place upon the sensitized plate a number of reproductions of such a design of an exact predetermined size and in accurate focus, such a step and repeat machine is impractical, if not incapable of doing this work. Still greater difficulty would be experienced with such machines in attempting to do multiple color work because the different unit transparencies are rarely of the exact relative sizes required for register, and each must be adjusted with great exactness to throw an image which will register with the other components of the complete color design. The size of an image must be varied by the relative adjustment of the lens. unit design and sensitized plate along the line of projection, and since in such a machine any adjustment for varying the size of the image will throw out a previously obtained focus of the image and vice versa, it will require great skill on the part of the operator and consume much time in separately adjusting these parts to obtain the desired size of image in proper focus. The time required in hitting upon the proper positions of these separately adjusted parts to give the exact desired size of the image in accurate focus, is entirely problematical and it requires, at best, a highly skilled operator who can judge of the accuracy of the focus of the image when obtained, and who can so manipulate the separately adjustable parts as to hit upon the proper relative adjustment of them with some degree of success.

We have found that in order to provide a successful step and repeat machine for practical uses, the machine should be of the lens type with adjusting mechanism so that the images can be projected in clear-cut lines and in different sizes; and that the machine should be so arranged and constructed that the image of the design to be reproduced should always be maintained in proper focus during the relative movements of the sensitized surface and the lens and unit design along the line of projection for varying the size of the image, and during the subsequent relative movements between the sensitized surface on the one hand and the lens and unit design on the other, in stepping and repeating the design upon the sensitized surface. In other words, the sensitized surface and the unit design should always be maintained in the conjugate foci of the lens, so that in setting the machine, it is only necessary for the operator to see that he has obtained the exact size of image on the screen, the image being always in focus. This is true not only where, in an original order, for one reason or another, it is necessary to have the reproductions of the design of an act predetermined size, but in the practical operations of step and repeat machines, even where the operator may determine for himself, within limits, the size of the reproduced design, it frequently happens that the machine must be left or altered for other work before the completion of a particular job, in which case it is essential to set the machine to reproduce the design exactly as originally started, such as in making different plates for multiple color work. Likewise, in a duplicate or second order for work previously done, it may be necessary to set the machine with absolute accuracy to reproduce the design in the exact predetermined size and focus in order that the prints may correspond with those first produced.

One of the objects of our invention is to provide a step and repeat machine by means of which the image of a design may be projected upon successive portions of a sensitized plate, in predetermined sizes, the same as or different from that of the unit original, the image being always maintained in proper focus throughout the relative movements of the sensitized plate and the lens and the unit design along the line of projection, and during the stepping and repeating of the image on the plate.

In carrying out our invention, we provide a step and repeat machine having a holder for the sensitized plate, a holder for the lens and a holder for the unit design, with automatic focus-maintaining mechanism for shifting two of these elements, for example, the lens and the unit design holder along the line of projection so as to continuously maintain the projected image in focus during the movements of these parts for adj usting the size of the image, and with means for producing relative movement between the sensitized plate holder on the one hand and the lens and object holder with its automatic focusing mechanism, on the other, transverse to the line of projection, without disturbing the adjustment of the parts along the optical axis.

Another object of our invention is the provision of a compact, accurate and durable automatic focus-maintaining apparatus.

The invention will be more readily understood and further objects of the invention will more fully appear from the following description taken in connection with the accompanying drawings which illustrate one embodiment of the invention.

Figure 1 is a side elevation of a machine embodying one form of the invention; Fig. 2 is an enlarged side elevation of the rear part of the machine shown in Fig. 1, partly in section; Fig. 3 is a sectional view on line 33 of Fig. 4; Fig. 4 is a rear elevation of the machine, partly in section; Fig. 5 is a vertical section on line 55 of Fig. 3, omitting some of the parts shown in Fig. 3; Fig. 6 is a diagrammatical illustration of the re lation of the lens to the image and object distances; and Figs. 7 and 8 are diagrammatical side elevations of the mechanism illustrated in Figs. 1, 2, 3 and 4.

Referring to the drawings (Figs. 1 and 2), the sensitized plate 90 to receive the image, is held vertically before the lens in a suitable plate-holding frame 91 shown by way of illustration as comprising uprights or side pieces 92 with suitable cross connections including two parallel horizontal rods 11. Upon the rods 11 is mounted a horizontally sliding carrier 10, and on this carrier the lens and object holders hereinafter referred to, are mounted. The carrier 10 is moved horizontally by means of a rack 93 (Fig. 3) cut in the lower surface of the lower horizontal rod 11, and with this rack meshesa pinion 94, the pinion being mounted on a sleeve 96 on shaft 20, which sleeve is rotated by a handle 95. This sleeve is journaled in the lower end of the carrier 10 so that as the handle 95 is rotated, the pinion, traveling along the rack, moves the carrier horizontally on the guide rods 11 on which the carrier is slidinglv mounted, thereby shifting the carrier with the lens and object holder thereon relative to the sensitized plate. transversely of the line of projection, so as to bring the lens and object holder opposite successive portions of the sensitized plate.

The carrier 10 is provided on its upper surface with parallel rearwardly extending guideways 12 (Figs. 2 to 5) on which is mounted a sliding frame 13 having depending side pieces 14 and a lens holder 15. The side pieces 14 are united by a vertical web 16 and a horizontal web 17 (Fig. 3), thus forming a substantial and rigid structure. The sliding frame 13 is provided on its top surface with guideways or rails 45 extending parallel with the guidevv'ays 12 on the carrier 10, and on these rails 45 is mounted a second sliding frame 40 carrying an object holder 46 on which is placed the phcttgraphic plate bearing the unit object or design to be reproduced upon the sensitized surface. At the rear end of the sliding frame 40 there is provided a box 48 con taining a suitable source of light. These slides are coupled together by the automatic focus-maintaining mechanism and they are moved back and forth on their guideways as will now be described.

The shaft 20 is grooved as shown at 20 and is provided with a cranlearm 21 at its front end, and on this shaft is mounted a spiral gear 22 having a feather engaging said groove so as to be free to move along the shaft, but rotating with it. The shaft is supported opposite the depending sides 14 of frame 13 by a yoke 23 secured to a bracket 24 (Figs. 3 and 4). This bracket is also provided with bearings for two parallel vertical shafts 25 (Fig. 4) to which are keyed spiral gears 26 meshing with the spiral gear which drives them. The lower ends of the vertical shafts are steadied in bracket 18 and their upper ends are journaled in bearings 27 extending from a bracket 27 secured to the horizontal web 17. Each shaft carries at its upper end a gear 28. which meshes with a gear 29 keyed on a horizontal threaded spindle 32 which is journaled at its rear end in the bracket 27. Lock nuts 47 bear against the rear surface of this journal and hold the gears 29 in mesh with the gear 28. The thread of the spindle engages with a nut 33 rigidly secured to the carrier 10, so that through the medium of the above described mechanism the sliding frame 13 is moved back and forth when shaft 20 is rotated by the crank arm 21. The parts of the vertical shafts 25 extending below the bracket 23 (Fig. 3) are provided with threads corresponding to the thread cut on the spindle 32. A yoke 34 (Fig. 4) is provided with threaded nuts engaging with the threads on the shafts 25 so that the yoke is raised or lowered simultaneously, and at the same rate as the sliding frame 13 is moved forward and backward when the crank handle 21 of the shaft 20 is rotated. This yoke drives or transmits movement to the automatic focus-maintaining mechanism in the following manner: The yoke 34 carries in its upper extremities pivot pins 35 (Figs. 2 and 5) passing through guide blocks 35 adapted to slide in vertical slots 19 in each depending side frame 14 of frame 13. The outerends of the pivot pins 35 carry the lower ends of two sliding rods 36 (Figs. 2 and 4) which occupy inclined positions on the outside of the side frames 14. These sliding rods 36 pass through swiveled guides 37 and extend upward through guides 38 pivoted to rock or oscillate in brackets 39 at the rear end of the objectholding slide 40. The oscillating guides 37 are pivcted in blocks 41 which are adjustable in the slots 42 by nuts 44 on screws 43. The blocks 41 do not slide in the slots 42 during the operation of the machine, but said adjustment is for the purpose of primarily establishing the relation between the slide 40 and the lens-holding slide 13, which is determined by the focal length of the lens used. thereby securing the necessary sharpness of the image projected on the sensitized plate. \Vhen this adjustment is once made for any particular lens, the blocks 41 then remain fixed in position and the rods 36 slide through the guides 37 which remain at a fixed point in the slots 42. the fixed position being obtained by adjusting the nuts 44 on the screws 43. This pivot or fulcrum point for a given lens will be at the intersection of two lines, one parallel to the line of movement of the connection of one of the sliding rods to the slide which it moves and at the focal distance of the lens from said line, the other line being parallel to the line of movement of the point of connection of said rod to the threaded shaft, or, in this case, parallel to the slot 19 in which the other end of the rod slides, and at the focal distance of the lens from said line or slot. The slot 42 along which the fulcrum point is adjusted should extend along a line passing through the point of intersection of these two lines for different lenses. Such a line will bisect the angle formed between the sl t 19 and the path of movement of the end of the rod connected to the sliding frame 40, and the slot 42 along which the fulcrum point is adjusted, will be at an angle of 45 degrees to the vertical slot 19.

If the shaft 20 (Fig. is rotated in a direction to impart a downward movement to the yoke 34, the studs at the ends of the yoke will draw the rods 36 downward also, the latter in their descent passing through the pivoted oscillating guides 37. As the lower ends of the rods move downward, the angle of inclination of the rods is changed, and the upper ends being thrown forward, move the slide 40 with the object plate and light. The rotation of the shaft 20, simultaneously imparts movement to the lens-holding slide 13 through the gears 22 and 26, shafts 25, gears 28, gear '29 and the spindle 32, in such proportion as to maintain at all times the proper relative position of the lens and the object with regard to the sensitized plate, the different positions causing the image to be of correspondingly different sizes as compared to the size of the object or unit design. This is shown diagrammatically in Figs. 7 and 8. In Fig. 7, the lens is shown equidistant between the object and the image plate so that equal reproduction is attained. In Fig. 8, the changed positions of the object and the lens produce an image three times the linear dimensions of the object. Fig. 6 is used to demonstrate the mathematical correctness of the focusing movement. The sides F of the square are equal to the focus of the lens used. Extending two sides 0L and OS until they intersect any line B swung through the intersection I of the two opposite sides 01' the square F, the lengths f, and

will be to each other as F (n+1) is to and are thus equal to the conjugate foci of the lens F for an object distance f, and the image distance 7. Let

f F:Y and f'-F:X and X nF then X:F:F:Y

nF F F: Y

Q. E. D.

The diagram of Fig. 6 demonstrates the distances f and f in direction at right angles to each other whereas in actual practice, they are mostly needed in a continued straight line.

Figs. 7 and 8 show how by gearing a horizontal rod representing the length F, to a vertical rod 7, to which the same movement is imparted in a vertical plane, the length 7" is obtained in the horizontal continuation of F. In Figs. 7 and 8 the vertical line on the left of the upper part of these figures indicates the image-receiving surface. These vertical lines are marked in Figs. 7 and 8 with the reference character I.

YVith the automatic focusing apparatus as described, if it is desired to produce an image on the sensitized plate larger than the unit design or object, the handle 21 ofthe shaft 20 is turned in the direction to cause the lower end of the rod 36 to move downward in the guideways 19, thereby throwing the upper end of the rod 36 to the left and forcing the object holder 46 toward the lens. During this operation the lens travels away from the sensitized plate, thus increasing the distance between the sensitized plate and the lens, and decreasing the distance between the object holder and the lens, which results in the image thrown on the plate being larger than the object. If it is then desired to reduce the image on the sensitized plate, the handle 21 will be turned in the opposite direction, causing the lens slide to move toward the sensitized surface, the rods 36 at the same time moving the object slide 40 rearwardly upon the lens slide, but inasmuch as the lens slide will approach the sensitized surface more rapidly than the object slide will move rearwardly upon the lens slide, the result of the movements will be that both the lens and the object will he brought nearer to the sensitized plate while the distance between the lens and the object will be increased in such manner as to maintain the focus, due to the principle of operation of the automatic focus-maintaining mechanism, as will be understood from the above set forth formula. In the particular embodiment of the invention shown, the rod 36 (Fig. 2) is shown in the position it assumes when the image and the object are of equal size; that is, when the transformation is in the ratio of one to one, and as shown, the lower end of the rod 36 at this time is near the upper end of the guideway 19.

The operation of the step and repeat machine can be exemplified as follows: A photographic reproduction of the unit design is placed in the object holder 46 and rays of light are projected through it and through the lens upon a focusing screen located in the plate holder which is subse quently to receive the sensitized plate. This projected image is then increased or diminished to the desired size by rotating the crank arm 21 which operates the sliding frames 13 and 40, as hereinbefore explained, while maintaining a sharp focus at all positions of the said frames. For instance, if it is desired to fill a space 16 inches square with 16 reproductions of an object or design, each image would be four inches square and this size of the different images of the object will be obtained by adjusting the positions of the lens and object with reference to the focusing screen, explained. When the exact size of the image on the screen has been obtained, suitable stops for limiting the successive movements of the carrier 10 are set and locked. T he focusing screen is then replaced by the sensitized surface upon which the designs are to be reproduced, and the handle 95 is then rotated to move the carrier 10 horizontally past the sensitized plate step by step and an exposure is made at each step, each succeeding image being brought into proper position on the plate adjacent the preceding image, until the desired number of images have been placed on the plate. \Ve thus secure a number of identical images suitably spaced upon the sensitized surface, which may be developed and from which printing surfaces may be prepared for lithographic work, or for printing on fabrics.

The arrangement and construction of the automatic focus-maintaining mechanism herein shown and described has been found to be very accurate and durable, and to a great extent if not entirely, eliminates maccuracies and lost motion which is found in most, if not all known forms of automatic focusing mechanism. By mounting one of the slides upon the other so that the slides may move together but at different rates, it is possible to provide very compact and durable automatic focus-maintaining connections between. the slides with relative short parts, thus lessening the liability of any buckling in the parts and reducing the possibility of strains and lost motion, as well as reducing the cost of manufacture of the apparatus. Likewise, by supporting these sliding parts on a bracket from the support for the sensitized plate the necessity of a large machine base is obviated and a rigid and durable supporting structure is obtained. Also, the feature of providing sliding oscillating rods as the connection between the two slides, forms an important part of our invention, and provides a compa ratively inexpensive and very durable and staunch means of linking these parts together so as to move them at the proper relative rates with the least possible friction or binding. Vith such automatic focusing mechanism, very fine accurate adjustments of the parts may be had for projecting images in exactly the desired size for the finest classes of Work.

While We have described our invention in connection with one embodiment thereof, it will be obvious to those skilled in the art that various modifications may be made with different arrangements and constructions of the parts Without departing from the spirit and scope of the generic invention, and we aim in the appended claims, to cover all such modifications as come within the scope of our invention.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent, is:

1. In a machine of the character described, the combination of a sensitized plate holder, a lens and an object holder, said plate holder and object holder being located in the conjugate foci of the lens, means for simultaneously altering the relative positions of the plate holder, lens and object holder along the line of projection while maintaining the said object holder and plate holder respectively in said conjugate foci, and means for producing relative movement between the sensitized plate holder on the one hand and the said lens and object holder on the ether hand, transverse to the line of projection, without disturbing the positions of the lens and object holder rela tive to the plate-holder along the line of projection, whereby successive clearly defined images of a predetermined size of a unit design may be projected on a sensitized plate.

2. In apparatus of the character described, the combination of a holder for a sensitized plate, a supporting frame extending rearwardly thereof, a slide on the frame, a lens connected with the slide to move therewith, a second slide and an object holder connected to move therewith, the plate holder and (bject holder being located in the conjugate foci of the lens, means connecting the two slides for simultaneously moving them along the line of projection so as to continuously maintain the plate holder and the object holder in the conjugate foci of the lens, and means for producing relative movement between the sensitized plate holder on the one hand and said lens and object holder on the other hand, transverse to the line of projection, without disturbing the positions of said lens and object holder relative to the plateholder along the line of projection, whereby successive clearly defined images of a predetermined size of an object may be projected on the sensitized plate.

3. In apparatus of the character described, the combination of a holder for a sensitized plate. a supporting frame extending rearwardly of the plate holder, a slide mounted on said frame, a lens connected with said slide to move therewith, a second slide mounted on the first and an object holder connected with the second slide to move therewith, the plate holder and object holder being located in the conjugate foci of the lens, means connecting the two slides for simultaneously moving them along the line of projection so as to continuously maintain the plate holder and the object holder in the conjugate foci of the lens, and means for producing relative movement between the sensitized plate holder on the one hand and said lens and object holder on the other hand, transverse to the line of projection, without disturbing the positions of said lens and object holder relative to the plate-holder along the line of projection, whereby successive clearly defined images of a predetermined size of an object may be projected on the sensitized plate.

4. In apparatus of the character described, the combination of a holder for a sensitized plate, a supporting frame extending rearwardly thereof, a slide on the frame, a lens connected with the slide to move therewith, a second slide and an object holder connected to move therewith, the plate holder and object holder being located. in the conjugate foci of the lens, automatic focus-maintaining mechanism connecting said slides for simultaneously shifting them along the line of projection so as to con tinuously maintain the plate holder in proper focus, said focusing mechanism comprising an oscillating sliding rod pivotally connected with the lens slide to move therewith along the line of projection and having a sliding pivotal connection with the second slide, and means for producing relative movement between the sensitized plate holder on the one hand and said lens and object holder on the other hand, transverse to the line of projection, without disturb' ing the positions of said lens and object holder relative to the plate-holder along the line of projection, whereby successive clearly defined images of a predetermined size of an object may be projected on the sensitized plate.

5. In a machine of the character described, the combination of a sensitized plate holder, a frame or support therefor, a supporting bracket supported from said frame and extending rearwardly thereof, a slide on said bracket and a lens connected with the slide to move therewith, a second slide mounted on the first slide and an object holder connected with said second slide to move therewith, the plate holder and object holder being located in the conjugated foci of the lens, automatic focusmaintaining mechanism connecting the two slides for simultaneously shifting them along the line of projection so as to continuously maintain the plate holder in proper focus, and means for producing relative movement between the sensitized plate holder on the one hand and the rearwardly extending frame and slides on the other hand, transverse to the line of projection, without disturbing the positions of said lens and object holder relative to the plate-holder along the line of projection, whereby successive clearly defined images of a predetermined size 'of an object may be projected on the sensitized plate.

6. In apparatus of the character described, the combination of the following elements: a lens, an object holder located in one of the conjugate foci of said lens, a supporting frame for said lens and object holder, a sensitized plate holder located in the other of the conjugate foci of said lens, means for simultaneously altering the positions of the lens and object holder along the line of projection relative to the sensitized plate holder while maintaining the object holder and plate holder respectively in said conjugate foci, and means comprising a rack, and a pinion engaging the same for producing relative movement between the sensitized plate holder on the one hand and the lens and object holder on the other hand. transverse to the line of projection, without distributing the positions of the object holder and lens relative to the plateholder along the line of projection, whereby successive clearly defined images of a predetermined size of an object may be projected on successive portions of the sensitized plate.

7. In apparatus of the character described, the combination of the following elements: a lens, an object holder located in one of the conjugate foci of said lens, a su 'iporting frame for said lens and object holder, a sensitized plate holder located in the other of the conjugate foci of said lens, and means for simultaneously altering the positions of the lens and ohiect holder along the line of projection relative to the sensitized plate holder while maintaining the plate holder and object holder respectively in said conjugate foci, said means including a. screw moving one of the movable memhers and means including one or more sliding pivoted rods connecting said screw with the other movable member to move the latter at a different rate from the first member.

8. In a machine of the character described, the combination of a sensitized plate holder, a support, a, slide on the support and a lens carried on said slide, a second slide and an, object holder carried thereon, said plate holder and object holder being located in the conjugate foci of the lens. means for simultaneously altering the relative positions of said lens, object holder and plate holder along the line of projection while maintaining the said object holder and plate holder respectively in said conjugate foci, said means including a threaded shaft for moving one of the slides and one or more pivoted sliding rods connecting the shaft and other slide to more said second slide simultaneously with the first when the shaftis rotated, but at a different rate from the first, and a guidewav for compelling the moven'ient of the sliding rod in an accurate line to maintain the focus and relieve the threaded shaft of side thrusts and s rains.

9. In apparatus of the character de scribed, the combination of a. support, a slide on the same, a lens carried on tl e slide, a holder for a sensitized plate, a Second slide and an object holder carried therein, said plate holder and object holder being located in the conjugate frci of the lens, means including a screw actuating the first slide along the line of projection, focus-maintaining mechanism including rods swiveled on the first slide to more therewith along the line of projection and slidinglv nd pivotally engaging with the second slide to more the latter, and means for simnltaneously operating the screw and rods \vhere iv tl e positions of the lens and object holder along the line of projection relative to the sensitized plate holder are altered so as to maintain the plate holder and object holder respectively in said conjugate foci.

10. In apparatus of the character described, the combination of a support, a holder for a sensitized plate, a slide on the support and a lens carried thereon, a second slide and an object holder carried thereon, said plate holder and object holder being located in the conjugate foci of the lens, means including one or more threaded shafts for moving the first slide, said shaft or shafts being at an angle to the path of movement of said slides, focus-maintaining means including one or more sliding rods fulcrumed on the first slide and engaging the second slide and operated from the said shaft or shafts to move the second slide relatively to the first and simultaneously therewith, means for adjusting the fulcrum of the rod or rods along a line bisecting the angle forn'ied between the threaded shaft and the line of movement of the point of connection of the rod or rods to the second slide, \vl'icreby the plate holder and object holder may be accurately positioned in the conjugate foci of said lens and there continuously maintained during movements of the lens and oliject holder.

11. In apparatus of th 0. character d escribed, the combination of a support. sensitized plate holder. a slide on the support and a lens carried on said slide, a second slide and an object holder carried thereon. said plate holder and obj Pct holder being located in the conjugate foci of the lens. means including a. threaded shaft for moving the first slide focus-maintaining means including one or n'iore sliding rods fulcrumed on the first slide and engaging the second slide and operatively connected With the threaded shaft to more the second slide relatively to the firs and simultaneously therewith, said fulcrumed point being located on the first slide at the intersection of two lines, one parallel to the line of movement of the point of connection of the rod or rods to the second slide and at the focal distance of the lens therefrom. and the other parallel to the screw-threaded shaft and at the focal distance of the lens from the line of movement of the point of connection of the rod or rods thereto, and means for operating said screwthreaded shaft whereby the two slides are moved simultaneously at such rates as to maintain the sensitized plate holder and the object holder in the conjugate foci of the lens.

12. In a 'iparatus of the character described, the combination or a support, a holder for a sensitized plate, a slide mounted on the support and a lens carried on said slide, a second slide and an object holder carried there on, said plate holder and o 'iject holder being located in the conjugate foci of the lens, a pair of parallel threaded shafts, a driving shaft geared thereto to rotate said parallel shafts, means operativelv connecting said parallel shafts with the first slide to move said slide along its support, and focus-maintaining means operatively connecting the parallel shafts n ith the second slide to move the latter at such a relative rate with respect to the first slide as to maintain the object holder and plate holder in said conjugate Tom.

13. In apparatus of the character described, the combination of a support, a holder for a sensitized plate. a slide mounted on the sup port and a lens carried on said slide, a second slide and an object holder carried thereon, said plate holder and object holder being located in the conjugate foci of the lens, a pair of parallel threaded shafts mounted on the first slide. a driving shaft, means gearing said shaft to said parallel shafts to rotate the latter. means operatively connecting said parallel shafts with the first slide, and focus-maintaining means including a pair of sliding rods fulcrunicd on the first slide and o niratirelv connected to said. parallel shafts and to the second slide to move the latter at a different rate with respect to the first slide to maintain the object holder and plate holder in said conjugate foci.

14. In apparatus of the character described, the combination of a sensitized plate holder, a support extending rearwardly thereof, a lens and an object holder, the sensitized plate holder and the object holder being in the conjugate foci of the lens. a slide for moving the lens along the support, a second slide on the first for moving the object holder along the support. and automatic focusniaintaining mechanism for moving said slides simultaneously one upon the other and at different rates along the support so as to continuously maintain the plate holder and object holder in the conjugate foci of the lens.

15. In apparatus of the character described, the combination of a holder for a sensitized plate, a supporting frame extending rearwardly thereof, a slide on the frame, a lens connected with the slide to move therewith, a second slide and an object holder connected to move therewith, the plate holder and object holder being located in the conjugate foci of the lens, focusmaintaining mechanism connecting the slides to move the second slide relatively to the first when the first slide is moved along the support to maintain the focus, said means comprising a lever slidingly fulcrumed on the first slide, a guide on said slide extending at right angles to the optical axis and a part movable along the guide and to which the lever is pivotally connected, the other end of the lever being pivotally connected with the second slide, said lever slidingly engaging one of its said pivotal connections, and means for simultaneously imparting movement to the first slide and to one end 01 said lever to move the slides simultaneously and one relative to the other.

16. In apparatus of the character described, the combination of a holder for a sensitized plate, a supporting frame extending rearwardly thereof and having a guideway formed thereon, a slide on the guide- "ay and a lens connected with the slide to move therewith, a second slide and an object holder connected to move therewith, the plate holder and object holder being located in the conjugate foci of the lens, means for moving the first slide along the supporting frame including a screw and a nut operating thereon, and means connecting said slides whereby the second slide is simultaneously shifted along the frames when the first slide is moved so as to continuously maintain the focus, said focus-maintaining means comprising a lever lying in an upright plane parallel to the optical axis and fulcrumed on the first slide to move therewith along the optical axis and having a pivotally sliding connection with the second slide, and means causing it to swing about its fulcrum as the first slide is moved.

17. In a machine of the character described, the combination of a holder for a sensitized plate, a slide and a lens connected with said slide to move therewith, a second slide and an object holder connected to move therewith, the plate holder and the object holder being located in the conjugate foci of the lens, a horizontal supporting frame extending rearwardly from the plate hold r and having a guideWay along which the two slides are adapted to be moved, means for moving the first slide along the horizontal frame including a rotatable shaft extending from the front part of the machine rearwardly and geared with the first slide, said shaft having an operating handle at its front end, and means connecting said slides whereby the second slide is simulta neously shifted along the frame when the first slide is moved so as to continuously maintain the focus, said focus-maintaining means comprising a lever fulcrumed on the first slide to move therewith along the optical axis, means for causing the lever to swing about its fulcrum point as the first slide is moved, and means pivotally mounted on the objrct slide and through which the lever is adapted to slide as it is swung about its fulcrum point on the first slide.

18. In a machine of the character described, the combination of a holder for a sensitized plate. a slide and a lens connected with said slide to move therewith, a second slide and an object holder connected to more therewith, the plate holder and Cl)- ject holder being located in the conjugate foci of the lens, a horizontal supporting frame extending rearwardly of the plate holder and provided with a track or guideway along which the slides are adapted to move, means for moving the first slide along the guideway including a screw extending along the supporting frame and a nut operating thereon, one mounted on said frame and the other on said first slide, and means connecting said slides whereby the second slide simultaneously shifted along the frame when the first slide is moved so as to continuously maintain the focus, said focusmaintaining means including levers arranged one on each side of the guideway for the slides and fulcrumed on the first slide and pivotally engaging the second slide.

19. In a machine of the character described, the combination of a holder for a sensitized plate, a slide and a lens connected with said slide to move therewith, a second slide and an object holder connected to move therewith, the plate holder and object holder being located in conjugated foci of the lens, a horizontal supporting frame at the rear of the plate holder having a guideway along which the slides are adapted to move, a rotatable operating shaft extending from the front part of the machine rearwardly and provided with an operating handle at its forward end, means operatively connecting said shaft with the first slide including a member movable along the shaft, with means operatively connecting said member to said first slide to move said slide along its guidewav, and means connecting said slides whereby the second slide is simultaneously shifted along the frame when the first slide is moved so as to continuously maintain the focus, said focusmaintaining means comprising a lever fulcrumed on the first slide, means for causing the lever to swing about its fulcrum point as the first slide is moved, and means pivotally mounted on the object slide and through which the lever is adapted to slide, as it is swung about its fulcrum point on the first slide.

20. In a machine of the character described, the combination of a holder for a sensitized plate, a slide and a lens connected with said slide to move therewith, a second slide and an object holder being located in the conjugate foci of the lens, a horizontal supporting frame at the rear of the plate holder having a guideway along which the slides are adapted to move, a rotatable operating shaft extending from the front part of the machine rearwardly and provided with an operating handle at its forward end, means operatively connecting said shaft with the first slide including a member movable along the shaft, with means operatively connected with said member and adapted to apply force to the first slide along a line parallel to its guideway to move said first slide along the guideway, and means connecting said slides whereby the second slide is simultaneously shifted along the frame when the first slide is moved so as to continuously maintain the focus, said focusmaintaining means comprising a lever lying in an upright plane parallel to the optical axis and fulcrumed on the first slide to move therewith along the optical axis and having a pivotally sliding connection with the second slide, and means causing it to swing about its fulcrum as the first slide is moved.

21. In a machine of the character described, the combination of a holder for a sensitized plate, a slide and a lens connected with said slide to move therewith, a second slide and an object holder connected to move therewith, the plate holder and object holder being in the conjugate foci of the lens, a horizontal supporting frame extending rearwardly of the plate holder and provided with a track or guideway along which the slides are adapted to move, means for moving the first slide along the guideway including a screw extending along the supporting frame and a nut operating thereon, one mounted on said frame and the other on said first slide, and means connecting said slides whereby the second slide is simultaneously shifted along the frame when the first slide is moved so as to continuously maintain the focus, said focus-maintaining means including levers one fulcrumed on each side of the first slide, means on the second slide slidingly engaged by said levers at one side of their fulcrums, and means operatively connecting the ends of the levers at the opposite side of their fulcrums to said screw to cause the levers to be swung about their fulcrums as the first slide is shifted.

In witness whereof, we have hereunto set our hands this 13th day of April, 1909.

LOUIS J. R. HOLST. OSCAR CHOUINARD. WVitnesses:

AGNES L. CLEINE, ANTHONY F. ARCOME.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. 0.

It is hereby certified that in Letters Patent No. 1,131,629, granted March 9, 1915,

upon the application of Louis J. R. Holst and Oscar Chouinard, of New York, N. Y.,

for an improvement in Step and Repeat Machines," errors appear in the printed specification requiring correction as follows: Page 2, line 4b, for the word act read exact; same page, line 89, after the word other insert the word hand; page 6, line 58, for the word conjugated read conjugate; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the-case in the Patent Office.

Signed and sealed this 4th day of May, A. D., 1915.

[31mm] R. F. WHITEHEAD,

Acting Commissioner of Patents.

Corrections in Letters Patent No. 1,131,629. 

